Nonwoven fabric for reinforcing foam molded articles and product using same

ABSTRACT

It is provided that a nonwoven fabric for reinforcing foam molded articles which is excellent in the dimensional stability in a cutting/sewing step, in the followability to a mold in a foam molding step, and gives a foam molded article with excellent appearance and durability. A nonwoven fabric for reinforcing foam molded articles formed by interlacing at least 2 filament nonwoven fabric layers with different apparent density, wherein the nonwoven fabric has dry heat shrinkage rate of −1 to 2% in both longitudinal and transverse directions at the time of heat treatment at 80° C. for 30 minutes and tear strength of 20 N or higher in both longitudinal and transverse directions.

TECHNICAL FIELD

The present invention relates to a nonwoven fabric for reinforcing foammolded articles, and particularly to a nonwoven fabric for reinforcingfoam molded articles which is suitable for reinforcing seat pads to beused for vehicular seat materials and to products using the nonwovenfabric.

BACKGROUND ART

As a vehicular seat material, a molded article of a foamed resin(hereinafter, referred to as foam molded article) united with a nonwovenfabric for reinforcement at the time of molding is used. This nonwovenfabric for reinforcing a foam molded article (hereinafter, referred toas nonwoven fabric for reinforcement) is arranged between a foamed resinand metal springs to exhibit functions of making the cushion action ofthe metal springs evenly and at the same time preventing the frictionalsound generated by contact of the metal springs and the foam moldedarticle.

For example, Patent Document 1 describes a nonwoven fabric forreinforcement obtained by layering filament nonwoven fabric layers withdifferent porosity, that is, layering a bulky layer and a dense layer.This nonwoven fabric for reinforcement is for preventing bleeding of afoamable resin by the dense layer at the time of molding a foam moldedarticle.

In recent years, as consumers request increasingly higher quality, adeeply drawing type foam molded article with high design properties hasbeen required more. However, when the nonwoven fabric for reinforcementdescribed in Patent Document 1 is used for a deeply drawing type foammolded article, since the nonwoven fabric for reinforcement is inferiorin the followability to a mold, there occurs a problem that a tear iscaused locally attributed to wrinkles and blisters and a foamable resinbleeds out through the tear to the surface of the bulky layer of thenonwoven fabric for reinforcement.

To avoid such a problem, Patent Document 2 describes a foam molded bodyreinforcing material composed of a dense layer and a base layer andhaving stress of 0.5 to 20 N/5 cm at the time of 5% elongation at 65° C.Although having good followability to a mold in the foam molding step,the foam molded body-reinforcing material described in Patent Document 2has a problem that a foamable resin sometimes bleeds out to the surfaceof the reinforcing material at the time of a foam molding step,depending on the type of the foamable resin and also that thedimensional stability of the foam molded body-reinforcing material isinferior in a cutting/sewing step.

Patent Document 3 describes a foamed urethane-reinforcing material withincreased stress of 18 N/5 cm or higher at the time of 5% elongation.

Although having good dimensional stability in the cutting/sewing step,the foamed urethane-reinforcing material described in Patent Document 3has a problem of inferior followability to a deep drawing type mold.

Patent Document 4 describes a nonwoven fabric with apparent density of0.06 to 0.15 g/cm³ and dry heat shrinkage rate of −0.5 to 0.5% at 65° C.Although having good followability to a mold in the foam molding step,the nonwoven fabric described in Patent Document 3 has a problem ofinferior durability of an obtained foam molded article.

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: JP-A-hei-6-171002

Patent Document 2: JP-A-2004-353153

Patent Document 3: JP-A-2007-331259

Patent Document 4: JP-A-2012-007259

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

Nonwoven fabric for reinforcement is conventionally known which hasbasic properties; that is, causing no bleeding of a foamable resin in afoam molded article, showing a good finishing form, and being excellentin suppressing frictional sound, flexural sound, reflection sound, etc;and additionally a property excellent in followability to a mold at thetime of foam molding.

However, in the step of cutting/sewing a nonwoven fabric forreinforcement in a form of a foam molded article, which is a step beforefoam molding a seat pad, at the time of a cutting work by drawing therolled nonwoven fabric for reinforcement, if the nonwoven fabric forreinforcement is provided with excess flexibility to satisfy thefollowability to a mold for foam molding, the nonwoven fabric forreinforcement is deformed due to the processing tension at the time ofdrawing and it results in a problem of decrease of workability.

Accordingly, the present invention aims to provide a nonwoven fabric forreinforcement excellent in the followability to a mold at the time offoam molding and suppressed from deformation attributed to theprocessing tension in a cutting/sewing step. Further, the presentinvention aims to provide a nonwoven fabric for reinforcement causing nobleeding of a foamable resin at the time of foam molding, giving a goodfinishing form of a foam molded article, and excellent in functions ofsuppressing frictional sound, flexural sound, reflection sound, etc.

Solutions to the Problems

The inventors of the present invention made various investigation toachieve the aim and found that a nonwoven fabric for reinforcement(hereinafter, referred to as a first nonwoven fabric for reinforcement)formed by interlacing at least 2 filament nonwoven fabric layers withdifferent apparent density and having base weight of 50-110 g/m²,thickness of 0.5-1.2 mm, 23 to 50 N/5 cm stress at the time of 5%elongation in longitudinal direction, 15 N/5 cm or lower stress at thetime of 5% elongation in transverse direction, and air permeability of50 to 250 cm³/cm²·sec is excellent in the dimensional stability in acutting/sewing step, in the followability to a mold in a foam moldingstep, and gives a foam molded article with excellent appearance anddurability.

In the first nonwoven fabrics for reinforcement, it is preferable thatthe fiber arrangement angle of the filament nonwoven fabric with thehighest apparent density is 5 to 60°.

The inventors of the present invention found that a nonwoven fabric forreinforcement (hereinafter, referred to as a second nonwoven fabric forreinforcement) formed by interlacing at least 2 filament nonwoven fabriclayers with different apparent density, wherein all of the nonwovenfabric layers have apparent density of higher than 0.15 g/cm³, and thenonwoven fabric has dry heat shrinkage rate of -1 to 2% in bothlongitudinal and transverse directions at the time of heat treatment at80° C. for 30 minutes and tear strength of 20 N or higher in bothlongitudinal and transverse directions is excellent in the dimensionalstability in a cutting/sewing step, in the followability to a mold in afoam molding step, and gives a foam molded article with excellentappearance and durability.

In the second nonwoven fabrics for reinforcement, it is preferable thatthe stress at the time of 5% elongation in longitudinal direction is 20to 45 N/5 cm and the stress at the time of 5% elongation in transversedirection is 19 N/5 cm or lower.

In the first and the second nonwoven fabrics for reinforcement, it ispreferable that the filament nonwoven fabrics are made of polyesterfibers.

Furthermore, the present invention includes a foam molded articlewherein the first and the second nonwoven fabrics for reinforcing foammolded articles is used as a reinforcing cloth, and a foam moldedarticle wherein the filament nonwoven fabric with higher apparentdensity between 2 layers of filament nonwoven fabric with differentdensity is arranged in the foamed body side of the foam molded article.

EFFECTS OF THE INVENTION

In the case of using either one of the first and the second nonwovenfabrics for reinforcement of the present invention (hereinafter, in thecase of referring simply to a nonwoven fabric for reinforcement, itmeans both of the first and the second nonwoven fabrics forreinforcement), no bleeding of a foamable resin is caused in a foammolded article and the foam molded article is excellent in a soundsuppressing property for frictional sound generated due to frictionbetween the foam molded article and metal springs of a seat. Further,the nonwoven fabric for reinforcement of the present invention isprovided with flexibility, excellent in the followability to a mold atthe time of foam molding, and has improved workability at the time ofdrawing the nonwoven fabric for reinforcement in a cutting/sewing step.Since being relatively lightweight, the nonwoven fabric forreinforcement of the present invention is useful for economicallyproducing a lightweight and high grade foam molded article andcontributes to making a vehicle using the foam molded article economicaland lightweight and also to saving energy in terms of driving thevehicle.

MODE FOR CARRYING OUT THE INVENTION

A nonwoven fabric for reinforcement of the present invention is anonwoven fabric obtained by interlacing at least 2 filament nonwovenfabric layers with different apparent density. That is, the nonwovenfabric for reinforcement of the present invention contains a layer of anonwoven fabric with higher apparent density (hereinafter, referred toas dense layer) and a nonwoven fabric with lower apparent density(hereinafter referred to as bulky layer). The dense layer is a layer tobring into contact with a foamed body and is of a filament nonwovenfabric having a function of preventing bleeding of a foamable resin in afoam molding step, suppressing elongation of the nonwoven fabric in thefiber arrangement direction at the time of drawing work of the nonwovenfabric in the cutting step, and being so improved in the fiberarrangement as to give mechanical characteristics for improving thefollowability to a mold at the time of foam molding, and contributing toimprovement of the dimensional stability in the cutting/sewing step. Onthe other hand, the bulky layer is a layer bringing into contact withmetal springs of a seat and is of a filament nonwoven fabriccontributing to suppression of frictional sound, flexural sound,reflection sound, etc., and providing a function of wear resistance anddurability.

Use of such filament nonwoven fabrics makes it possible to cause evendeformation in the foam molding step, so that tears are hardly formed,the appearance of a foam molded article becomes good, and at the sametime, the durability can be improved. However, in the case of usingshort fiber nonwoven fabric, tears tend to be formed easily because ofuneven deformation in the foam molding step. Still further, in the casea dense layer is a short fiber-nonwoven fabric layer, since there is nocontinuity of fibers, the mechanical characteristics with low baseweight are inferior, and since the followability to a mold differslocally at the time of molding, deformation and breakage tend to becaused undesirably.

The dense layer and the bulky layer are interlaced and joined to give anonwoven fabric for reinforcement with a structure in which the fiberscomposing the filament nonwoven fabric of the bulky layer are extrudedto the surface of the dense layer (hereinafter, referred to extrudedfiber structure). As a result, the nonwoven fabric for reinforcement issoftened and provided with excellent followability to a mold, and at thetime of foam molding, the entire body of the foam molded article isunited owing to an anchor effect of the extruded fiber structure to givethe foam molded article provided with improved durability, too. Thisnonwoven fabric for reinforcement can be remarkably improved in thehandling property at the time of the nonwoven fabric-drawing work byincreasing the elongation stress in a low elongation range and thussuppressing the elongation and moreover can be excellent in themoldability, sound suppression properties, and durability.

The base weight of the nonwoven fabric for reinforcement is 50 g/m² orhigher and preferably 60 g/m² or higher. The base weight of the nonwovenfabric for reinforcement is 110 g/m² or lower and preferably 100 g/m² orlower. If the base weight is less than 50 g/m², a foamable resin maypossibly bleed out in the foam molding step and since the tearpropagation strength of the nonwoven fabric for reinforcement islowered, the durability of the foam molded article may possibly beworsened. If the base weight exceeds 110 g/m², it may possibly result infailure to meet the need of lightweight of a vehicle.

Thickness of the nonwoven fabric for reinforcement is 0.5 to 1.2 mm andpreferably 0.6 to 1.0 mm. If the thickness is less than 0.5 mm, theshutting function for a foamable resin is lowered to cause bleeding insome cases. If the thickness exceeds 1.2 mm, the followability to a moldis worsened at the time of foam molding, resulting in defective moldingin some cases.

The nonwoven fabric for reinforcement of the first aspect of the presentinvention has stress of 23 to 50 N/5 cm at the time of 5% elongation inlongitudinal direction and stress of 15 N/5 cm or lower at the time of5% elongation in transverse direction. If the arrangement of fibers ofthe filament nonwoven fabric is made evenly in the longitudinaldirection, the stress at the time of 5% elongation in the longitudinaldirection becomes high and the stress at the time of 5% elongation inthe transverse direction becomes low.

In order to prevent deformation of a nonwoven fabric due to drawingtension in the cutting step, improve the cutting property, and improvethe followability to a mold at the time of foam molding, the stress ofthe nonwoven fabric for reinforcement at 5% elongation in thelongitudinal direction is 23 to 50 N/5 cm and preferably 30 to 45 N/5cm. If it is less than 23 N/5 cm, the nonwoven fabric is deformed due tothe drawing tension in the cutting/ sewing step and the workability islowered and it consequently results in failure of stable cutting orsetting the nonwoven fabric in a mold. If it exceeds 50 N/5 cm, thefollowability to a mold at the time of foam molding is lowered and itresults in an inferior finishing form, tears, wrinkles, etc.

The nonwoven fabric for reinforcement of the first aspect of the presentinvention has stress of 15 N/5 cm or lower, preferably 5 to 14 N/5 cm,and more preferably 8 to 12 N/5 cm at the time of 5% elongation intransverse direction. If it exceeds 15 N/5 cm, the followability to amold is worsened and consequently, the finishing form becomes worse insome cases. If it is less than 5 N/5 cm, when tension is applied in thetransverse direction in the cutting/ sewing step, the nonwoven fabricmay possibly be elongated or deformed and the followability to a moldmay be different in the longitudinal and transverse directions at thetime of foam molding, so that finishing form of a molded article maypossibly be worsened and the nonwoven fabric may be torn in some cases.

The nonwoven fabric for reinforcement of the second aspect of thepresent invention has preferably stress of 20 to 45 N/5 cm at the timeof 5% elongation in longitudinal direction. The nonwoven fabric forreinforcement of the second aspect of the present invention haspreferably stress of 19 N/5 cm or lower and more preferably 5 to 19 N/5cm at the time of 5% elongation in transverse direction. If it is lessthan 5 N/5 cm, the processing defect may sometimes be caused even in thecase where desired stress is applied at the time of 5% elongation in thelongitudinal direction.

If the stress of the nonwoven fabric for reinforcement of the secondaspect of the present invention at the time of 5% elongation in thelongitudinal direction is less than 20 N/5 cm, the nonwoven fabric forreinforcement may sometimes be deformed due to the drawing tension inthe cutting/ sewing step and the cutting may become unstable. If thestress at the time of 5% elongation in the longitudinal directionexceeds 45 N/5 cm, wrinkles may possibly be formed in a foam moldedarticle. If the stress at the time of 5% elongation in the transversedirection is less than 5 N/5 cm, when tension is applied in thetransverse direction in the cutting/ sewing step, the nonwoven fabricmay possibly be elongated or deformed and the followability to a moldmay be different in the longitudinal and transverse directions at thetime of foam molding, so that the appearance of a foam molded articlemay possibly be worsened and the nonwoven fabric for reinforcement maybe torn in some cases. If the stress at the time of 5% elongation in thetransverse direction exceeds 19 N/5 cm, the followability to a mold isworsened and consequently, the finishing form becomes worse in somecases.

Long fibers to be used for the nonwoven fabric for reinforcement can beobtained by melt spinning and the nonwoven fabric for reinforcement canbe produced by pulling long fibers obtained by melt spinning with anejector and thereafter collecting the long fibers on a conveyor net. Thespinning speed is preferably 3500 m/min or higher preferably 4000 m/minor higher. If the spinning speed is less than 3500 m/min, wrinkles tendto be formed at the time of thermal bonding of the filament nonwovenfabric by embossing rolls.

To keep the stress at the time of 5% elongation of the dense layerwithin the above-mentioned preferable range, the fiber arrangement ispreferably tilted at 5 to 60° and more preferably 10 to 30° in theendless direction of the conveyor net (hereinafter, referred to as“endless direction”). The fiber arrangement angle is measured bymeasuring the arrangement angles for 100 fibers at arbitrary 5 pointsand averaging the measured angles to employ the average value as thefiber arrangement angle. In the case where all of fibers of the nonwovenfabric are arranged in the longitudinal direction (MD direction), thefiber arrangement angle becomes 0° and in the case where all of fibersof the nonwoven fabric are arranged in the transverse direction (TDdirection), the fiber arrangement angle becomes 90°.

In the filament nonwoven fabric production step, in order to arrange thelong fibers, which flow downstream together with a pulling fluid andaccompanied current (hereinafter, referred to “following current”) andwhich are drawn and hardened, slantingly at 10 to 30° to the endlessdirection, the following current on the pulling conveyor net surface inthe width direction and the following current in the directionpenetrating the conveyor net surface (hereinafter, referred to as“perpendicular direction”) are suppressed and meanwhile the followingcurrent in the endless direction is increased slightly more. As aresult, the fibers are arranged more in the endless direction. As afollowing current adjustment method, there are some ways: that is,installing baffles for the following current in the rim parts in thewidth direction of the conveyor net surface, lowering the suction blowspeed of the following current in the perpendicular direction, etc.Consequently, the fiber arrangement angle can be adjusted. For example,if baffles for following current with some cm height are installed inthe rim parts of the conveyor net in the width direction to control thesuction blow speed to be 3.0 to 9.0 m/s, a filament nonwoven fabric withfiber arrangement angle of 20 to 28° can be obtained. Additionally, apunching metal, a wire gauze, or the like may be used as the baffles forfollowing current.

The nonwoven fabric for reinforcement is composed of a dense layer and abulky layer. The dense layer is preferable to be formed by arrangingfibers more in the direction close to the longitudinal direction; thatis the fiber arrangement angle is narrow. On the other hand, the fiberarrangement angle is not particularly limited in the case where the baseweight of the nonwoven fabric for reinforcement is low, but in the casewhere the base weight of the nonwoven fabric for reinforcement is high,in order to keep the stress at the time of 5% elongation in thetransverse direction of the nonwoven fabric for reinforcement not be toohigh, the filament nonwoven fabric is preferable to have a bulky layerwith a narrow fiber arrangement angle similarly to that of the denselayer. It is because if the base weight of the nonwoven fabric forreinforcement is high, the base weight of the bulky layer is often high,too, and in such a case, if the filament nonwoven fabric in which thefibers are arranged more in the longitudinal direction is not used asthe bulky layer, it becomes difficult to keep the stress at the time of5% elongation in the transverse direction of the nonwoven fabric forreinforcement to be obtained below the prescribed stress.

In the nonwoven fabric for reinforcement of the present invention, theratio of the stress at the time of 5% elongation in the longitudinaldirection and the stress at the time of 5% elongation in the transversedirection (stress at the time of 5% elongation in the longitudinaldirection÷stress at the time of 5% elongation in the transversedirection) is preferably 2.2 or higher, more preferably 3 to 14, andeven more preferably 4 to 7. If the ratio of the stress at the time of5% elongation in the longitudinal direction and the stress at the timeof 5% elongation in the transverse direction is lower than 2.2, thefiber arrangement may become a random structure and the stress at thetime of 5% elongation in the longitudinal direction becomes low and thedimensional stability in the cutting/ sewing step may be inferior insome cases. If the ratio of the stress at the time of 5% elongation inthe longitudinal direction and the stress at the time of 5% elongationin the transverse direction exceeds 14, the fiber arrangement may becometoo linear and the stress at the time of 5% elongation in the transversedirection becomes low and the transverse elongation may be caused easilywith low stress and the followability to a mold may significantly differin the longitudinal and transverse directions, so that the finishingform of a molded article may be worsened in some cases. If the ratioexceeds 14, tears due to elongation deformation in the transversedirection may also be formed in some cases.

At the time of thermal bonding of the filament nonwoven fabric at 140 to215° C. by embossing rolls, the linear pressure is preferably 10 to 80kN/m and more preferably 30 to 70 kN/m.

If the temperature in the embossing process is made high to avoid thedry heat shrinkage rate to be high, it becomes difficult for the fibersto be interlaced and bonded in the interlacing step for the dense layerand the bulky layer and the tear strength of the nonwoven fabric forreinforcement becomes low and therefore, the durability of a foam moldedarticle may sometimes be inferior. If the linear pressure of theembossing rolls is less than 10 kN/m, the press bonding may be unevenand if the linear pressure exceeds 80 kN/m, it becomes difficult for thefibers to be interlaced and bonded in the interlacing step for the denselayer and the bulky layer and the tear strength of the nonwoven fabricfor reinforcement becomes low and therefore, the durability of a foammolded article may sometimes be inferior.

The interlacing method for the dense layer and the bulky layer in thepresent invention is not particularly limited but it is preferable tocarry out the interlacing treatment by needle-punching for forming apreferable extruded fiber structure in the surface of the dense layer.In the above-mentioned interlacing treatment by needle punching, it ispreferable that the needle density is 30 to 300 needles/cm² to form apreferable extruded fiber structure. Further, the degree of the extrudedfiber structure formation by needle punching depends on the needlepenetration state. The depth to which the first varve of needlespenetrates the nonwoven fabric is preferably 9 to 12 mm. If thepenetration depth is less than 9 mm, it becomes difficult to form apreferable extruded fiber structure and if the penetration depth exceeds12 mm, the hole diameter becomes large and the foamable resin maypossibly bleed out in the foam molding step.

The base weight of the filament nonwoven fabric to be used for the denselayer of the present invention is 20 g/m² or higher and preferably 30g/m² or higher. Still more, the base weight is preferably 90 g/m² orlower, more preferably 80 g/m² or lower, and even more preferably 70g/m² or lower. Thickness of the filament nonwoven fabric to be used forthe dense layer of the present invention is preferably 0.2 mm orthicker, more preferably 0.3 mm or thicker, and even more preferably 0.4mm or thicker. Still more, thickness is preferably 1.0 mm or less, morepreferably 0.9 mm or less, even more preferably 0.8 mm or less and mostpreferably 0.6 mm or less. If the tensile strength and tear strength arehigh even if the base weight is low, the function of shutting thefoamable resin is remarkably improved at the time of foam molding.

Further, the dense layer is preferable to have an extruded fiberstructure formed by interlacing and bonding fibers composing thefilament nonwoven fabric, which forms the bulky layer, in the foamedbody face side. Owing to the extruded fiber structure, the filamentnonwoven fabric itself is made soft by carrying out the interlacingtreatment while keeping the function of shutting a foamable resin, sothat the nonwoven fabric for reinforcement can be provided withfollowability to a mold that is an evenly deformable property. Stillmore, the anchor effect for firmly uniting the nonwoven fabric forreinforcement and a foamed body can be caused by embedding the extrudedfiber structure in the foamed body.

In terms of improvement of the durability of a foam molded article, thenonwoven fabric for reinforcement of the second aspect of the presentinvention is required to have higher than 0.15 g/cm³ apparent density ofthe dense layer and the bulky layer and the apparent density of thedense layer is preferably 0.16 to 0.18 g/cm³ and the apparent density ofthe bulky layer is preferably 0.155 to 0.165 g/cm³. If the apparentdensity of the dense layer and the bulky layer is too high, it becomesdifficult for the fibers to be interlaced in the interlacing step forthe dense layer and the bulky layer and it may result in failure toobtain a desired tear strength in some cases.

Since required to have a function as a shutting layer for shuttingleakage of a foamable resin to the surface of the nonwoven fabric forreinforcement at the time of foam molding, the filament nonwoven fabricof the dense layer is preferable to have independent dot-like partiallypress-bonded parts. After the interlacing treatment of the dense layerand the bulky layer, the dense layer is also softened. That is usefulfor reliably retaining followability to a mold at the time of a moldingprocess, keeping gas leakage at the time of foaming, and preventingblisters of a molded article. Formation of independent dot-likepartially press-bonded parts in the filament nonwoven fabric of thedense layer can cause a structure fixation effect; that is, theindependent press-bonded fiber assembly parts work as bonding points forfirmly fixing the constituent long fibers. The parts made flat otherthan the dot-like partially press-bonded parts provide the dense layerwith a shutting layer effect. As a result, the dense layer has a properair permeability and also has a function of easily following deformationby foam molding and a degassing function.

If no press-bonding treatment is carried out for the filament nonwovenfabric of the dense layer, the tear strength is lowered because oflowering of the nonwoven fabric strength and at the same time, thefunction of shutting a foamable resin is lowered and the foamable resinmay bleed out in the foam molding step in some cases.

In the case where the press-bonding treatment is carried out for theentire surface of the filament nonwoven fabric, even if the dense layeris softened by the interlacing treatment, the deformability at the timeof foam molding becomes inferior and the air permeability is lowered anda foam molded article may float in a mold in the foam molding step insome cases. Further, if the press-bonded parts are successivelycontinued, the flexibility is worsened so that deformation may becomedifficult in the foam molding step.

The surface area ratio of the partially press-bonded parts in thefilament nonwoven fabric of the dense layer is not particularly limited,but it is preferably 5 to 40%, more preferably 8 to 25%, and even morepreferably 10 to 20%. If it is less than 5%, the mechanicalcharacteristic may be lowered in some cases. Further, the shuttingfunction for a foamable resin becomes insufficient and bleeding of thefoamable resin may be caused in some cases. If it exceeds 40%, thefollowability to a mold may possibly become inferior in some cases.

A method for forming independent partially press-bonded parts in thefilament nonwoven fabric is not particularly limited. In the presentinvention, a conventional method, for example, embossing rollerprocessing may be employed. The form of the partially press-bonded partsis also not particularly limited if they are independent dots andexamples may be weave patterns, diamond patterns, square patterns,hexagonal patterns, oval patterns, check patterns, polka-dot patterns,round patterns, etc.

It is preferable that an extruded fiber structure is formed in the faceof the dense layer bringing into contact with a foamed body. Still more,the anchor effect for bonding and firmly uniting the foamed body and thedense layer can be caused by embedding the extruded fiber structure inthe foamed body. In the case where no extruded fiber structure is formedin the face of the dense layer bringing into contact with the foamedbody, the bonding force of the foamed body and the dense layer becomesinsufficient and it is possible that the foamed body and the nonwovenfabric for reinforcement are easily separated from each other.

The base weight and the thickness of the filament nonwoven fabric to beused for the dense layer and the bulky layer are not particularlylimited. The base weight is preferably 20 to 90 g/m², more preferably 20to 80 g/m², and even more preferably 30 to 70 g/m². Thickness ispreferably 0.3 to 1.0 mm and preferably 0.4 to 0.9 mm.

Air permeability of the nonwoven fabric for reinforcement of the firstaspect of the present invention is 50 to 250 cm³/cm²·sec and preferably75 to 200 cm³/cm²·sec. If the air permeability is less than 50cm³/cm²·sec, the expanded air discharge degree at the time of foammolding become uneven and it may results in defects, resin removal, orthe like in some cases. If it exceeds 250 cm³/cm²·sec, bleeding becauseof foamable resin leakage may occurs in some cases.

The fineness of long fibers to be used for the dense layer and the bulkylayer is not particularly limited, but in terms of exhibition of thefoamable resin shutting function, the reinforcing function, and thecushion function of the filament nonwoven fabric, it is preferable to be1.0 to 6 dtex and more preferable to be 1.5 to 4 dtex.

In terms of improvement of durability of a foam molded article, tearstrength of the nonwoven fabric for reinforcement of the second aspectof the present invention in both longitudinal and transverse directionsis required to be 20 N or higher and preferably 30 N or higher. However,if the tear strength is too high, it is sometimes impossible to obtaindesired stress at the time of 5% elongation.

In terms of suppression of wrinkle formation in the foam molding step,dry heat shrinkage rate at the time of heat treatment at 80° C. for 30minutes of the nonwoven fabric for reinforcement of the second aspect ofthe present invention is required to be −1 to 2% and preferably −0.5 to0.5% in both longitudinal and transverse directions. If the dry heatshrinkage rate is too low, not only wrinkles tend to be formed easily,but also flexibility is worsened and deformation may become difficult inthe foam molding step. If the dry heat shrinkage rate is too high, notonly wrinkles tend to be formed easily, but also a foam molded articlemay sometimes float in a mold in the foam molding step.

The nonwoven fabric for reinforcement of the present invention ispreferable to have a double layer structure composed of a dense layerand a bulky layer and may additionally have a middle layer unitedlyformed between the dense layer and the bulky layer and a nonwoven fabricto be used for the middle layer is not particularly limited. The middlelayer may be used as a shutting layer.

Materials for the filament nonwoven fabric to be used for the denselayer and the bulky layer of the present invention are not particularlylimited, but filament nonwoven fabrics made of polyester type resinswith a high function of shutting a foamable resin and good followabilityto a mold are preferable.

Examples of the polyester type resins may include homo-polyesters suchas poly(ethylene terephthalate) (PET), poly(butylene terephthalate)(PBT), poly(butylene naphthalate) (PEN), poly(cyclohexanedimethylterephthalate) (PCHT), poly(propylene terephthalate) (PTT), etc., andtheir copolymers and mixtures.

In the case where a temperature for foam molding of a foamed body ismade low, if poly(ethylene naphthalate) or polycarbonate having glasstransition temperature exceeding 100° C. is used as the materials forthe filament nonwoven fabric, the followability to a mold at the time offoam molding may become inferior in some cases. Therefore, in the casewhere, for example, a foamable polyurethane is processed by foam moldingat low temperature, polyester resins with melting point of 220° C. orhigher and glass transition temperature of less than 80° C. arepreferable.

Examples of such polyester type resins may be homo-polyesters such aspoly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT),poly(butylene naphthalate) (PBN), poly(propylene terephthalate) (PTT),etc., and their copolymers and mixtures. The polyester resins arepreferably polyester resins with glass transition temperature of 70° C.or lower. Most desirable polyester resins are poly(ethyleneterephthalate) (PET) and copolymers containing ethylene terephthalate asa main constituent units.

If necessary, a reforming agent such as an antioxidant, a light-proofagent, a coloring agent, an antibacterial agent, a flame retardant, ahydrophilizing agent, etc. may be added to an extent that thecharacteristics of the nonwoven fabric for reinforcement are notdeteriorated.

A nonwoven fabric for reinforcement satisfying the above-mentionedrequirements of the present invention is cut in a prescribed form andset in a molding due for cushions as a reinforcing cloth for foam moldedarticles in a manner that the face of the extruded fiber structure is inthe foamable resin side (that is, the dense layer is in the foamableresin side of a foam molded article) and thereafter foamed to obtain afoam molded article made of urethane foam. A cold foam molding method ora hot foam molding method may be employed as the foam molding method.The foam molded article is formed in a good finishing form, free frombleeding of the foamable resin, excellent in shape retention durabilityand wear resistance and, as a spring receiving material, capable ofsuppressing frictional sound, flexural sound, and reflection sound. Theoperationability in the cutting step into a prescribed form and forsetting on a mold is remarkably good without deformation of the nonwovenfabric.

The nonwoven fabric for reinforcement of the present invention can beused for various kinds of interior materials for vehicles and alsoconstruction materials, surface-foamed molded articles for electronicproducts as a nonwoven fabric for reinforcement, but not limited forcushions of seats of vehicles.

The present application claims the benefit of the priority date ofJapanese patent application No. 2012-127510 filed on Jun. 4, 2012 andNo. 2012-127511 filed on Jun. 4, 2012. All of the contents of theJapanese patent application No. 2012-127510 filed on Jun. 4, 2012 andNo. 2012-127511 filed on Jun. 4, 2012, are incorporated by reference.

EXAMPLES

Hereinafter, the present invention will be described more in detail withreference to Examples and Comparative Examples, but the presentinvention should not be limited to these Examples.

Evaluation methods employed for Examples of the present invention andComparative Examples are as follows.

(1) Fineness [dtex]

Arbitrary 5 points in one face and the other face of each layer wereselected and single fiber diameter of 20 single fibers (n =20) wasmeasured by an optical microscope and the average value was defined asan average single fiber diameter (D).

Fibers at the same 5 points were taken out and using a gradient densitytube, the specific gravity of the fibers (n=5) was measured and theaverage value was defined as average specific gravity (ρ). Next, theaverage single fiber cross sectional surface area was calculated fromthe average single fiber diameter and fiber weight per 10000 m wascalculated from the calculated value and the average specific gravityand defined as fineness (dtex). In addition, at the time of fiberdiameter measurement, if the fiber diameter of hollow fibers or the likewas difficult to be determined, it was measured from the fiber crosssection of a SEM photograph.

(2) Base Weight [g/m²]

Measurement was carried out according to “Weight per unit surface area”in JIS L1913:2010.

(3) Thickness [mm]

Thickness was measured at a load of 20 gf/cm² according to “Thickness”in JIS L1913:2010.

(4) Apparent Density [g/cm³]

The apparent density was calculated from the base weight measured in theforegoing (2) and the thickness measured in the foregoing (3) accordingto the following equation.

Apparent density=Base weight÷(thickness×1000)

(5) Mechanical Characteristic of Nonwoven Fabric

According to “Tensile strength and elongation” in JIS L1913 6.3: 2010,specimens at arbitrary 5 points were cut out in standard atmosphere (22°C.) and a elongation load curve until rupture was measured for therespective specimens (n =5) and the over-all average of respectivevalues was calculated.

(5-1) Stress at the Time of 5% Elongation [N/5 cm]

The stress [N/5 cm] at the time of 5% elongation at 22° C. was definedas the stress at the time of 5% elongation.

(6) Air Permeability (cm³/cm²·sec)

Air permeability was measured by a Frazier air permeability measurementapparatus according to JIS L1913 6.8.1: 2010.

(7) Judgement of Nonwoven Fabric

Whether a coating layer was a short fiber-nonwoven fabric or not wasdetermined by pulling out composing fibers and confirming that thefibers in short fiber state by eye observation. Whether a dense layerwas of a filament nonwoven fabric or not was determined by peeling aninterlaced other fiber-nonwoven fabric layer (including the extrudedfiber structure part) and confirming that the dense layer was composedof long fibers by eye observation.

(8) Surface Area Ratio of Partially Press-Bonded Parts of FilamentNonwoven Fabric

The filament nonwoven fabric of the dense layer was separated from thefilament nonwoven fabric (including the extruded fiber structure part)of the bulky layer to obtain a specimen and cut in a 30 mm square atarbitrary 20 points and photographed in 50 times magnification by a SEM.The obtained photograph was printed in an A3 size and the press-bondedunit surface area was cut off to measure the surface area (S0). Next,only a press-bonded part was cut out in the press-bonded unit surfacearea and the press bonded dot surface area (Si [mm²]) of eachpress-bonded part was measured and the average value was determined tobe the press-bonded dot surface area of the partially press-bonded part.The surface area ratio (P [%]) of partially press-bonded parts wascalculated from the integrated value of press-bonded surface areas(ΣSi=Sp) according to the following equation.

P=Sp/S0(n=20)

(9) Drawing Deformation of Nonwoven Fabric

Using a nonwoven fabric with width of 5 cm according to “Tensilestrength and elongation” in JIS L19136.3: 2010, elongation recoverytreatment with elongation stress of 20 N/5 cm in the longitudinaldirection was carried out 10 times and each specimen was left for 1 hourand the elongation deformation of the nonwoven fabric in thelongitudinal direction and state change by eye observation weremeasured.

In the case elongation deformation was less than 5% (no state change):◯; in the case where elongation deformation was 5% or higher and lessthan 10% (state change was slight): Δ; and in the case where elongationdeformation was 10% or higher (state change occurred): ×.

(10) Foam Moldability

A nonwoven fabric for reinforcement which was cut in prescribed form wasset in a cushion pad mold in a manner of adapting the nonwoven fabricfor reinforcement to adapt to the form of the mold and the setting statewas evaluated as followability to a mold by function evaluation. Next,2-liquid type urethane resins (isocyanate: San Foam (registered tradename) RC-1026, manufactured by Sanyo Chemical Industries, Ltd./polyol:San Foam (registered trade name) IC-505N, manufactured by Sanyo ChemicalIndustries, Ltd.=1/2.5 (weight ratio) were subjected to cold foaming(foam volume: width 460 mm×length 380 mm×depth 50 mm) at 65° C. and eachmolded article was evaluated by eye observation.

(10-1) Followability to a Mold

Easy to adapting to the mold and to be set in the mold: ◯; easy to getalong with the mold but hard to be set in the mold: Δ; and hard toadapting to the mold and to be set in the mold: × and those marked with◯ and Δ were determined to be practically applicable.

(10-2) Bleeding

Bleeding was evaluated by eye observation as follows: no bleeding of theurethane resins to the surface of a nonwoven fabric for reinforcement ofa molded article: ◯, slight bleeding: Δ; and apparently bleedingobserved: ×.

(10-3) Tearing

Tearing was evaluated by eye observation as follows: no tear in the faceof the nonwoven fabric for reinforcement of a molded particle: ◯,immediately before tearing: Δ; and tears observed: ×.

(10-4) Property of Adapting to Mold

Eye observation was carried out as follows: the face of the nonwovenfabric for reinforcement of a molded article was conformed to the formof the mold: ◯; slightly unmatched form: Δ; and apparently unmatched: ×.

(10-5) Wrinkle

Evaluation was done as follows: no wrinkle formed in the face of thenonwoven fabric for reinforcement of a molded article: ◯ and wrinkleswere formed in the face of the nonwoven fabric for reinforcement of amolded article: × and those which were marked with ◯ were determined tobe practically applicable.

(11) Evaluation of Sound Suppression of Molded Article

A molded article (cushion pad) was set in an actual vehicle and thevibration sound and frictional sound were heard for 1 hour flat landdriving test at 60 km/h and thus functional evaluation was carried outas follows: quiet as compared with the case where a molded article(cushion pad) having no nonwoven fabric for reinforcement: ◯ and samequietness: ×.

(12) Dry Heat Shrinkage Rate

Specimens were cut out at arbitrary 3 points and according to “Dry heatshrinkage rate” in JIS L 1913 6.3: 2010, and the specimens were heatedin an oven at 80° C. (model: PHH-101, manufactured by Tabai Espec Corp.)for 30 min. while being held in no tension state. After the treatment,the shrinkage rate was measured and its average value was determined tobe dry heat shrinkage rate.

(13) Tear Strength

Specimens were cut out at arbitrary 3 points in the longitudinal andtransverse directions and measurement was carried out according to “Tearstrength (single tongue method)” in JIS L 1913 6.3: 2010 and the averagevalue was determined to be tear strength.

Example 1

Poly(ethylene terephthalate) (hereinafter, abbreviated as “PET”) withintrinsic viscosity of 0.65 dl/g was melt-spun at spinning temperatureof 290° C. and single hole discharge amount of 1.0 g/min out of a nozzlewith a round cross section and opened while being pulled at a spinningspeed of 4500 m/min and dropped on a conveyor belt below. Baffles forfollowing current having 2 cm height and made of a punching metal wereinstalled in the rim parts in the width direction of the conveyor netand the suction blow speed was controlled to be 8 m/s to obtain a webwith the base weight of 30g/m² composed of long fibers with fineness of2.2 dtex. Next, using embossing rollers having oval patterns andpress-bonding surface area of 18%, an embossing process was carried outsuccessively at embossing temperature of 200° C. and linear pressure of40 kN/m to obtain a filament nonwoven fabric for dense layers made ofcontinuous fibers with 2.2 dtex and having base weight of 30 g/m², fiberarrangement angle of 22°, and apparent density of 0.185 g/cm³.

PET with intrinsic viscosity of 0.65 dl/g was melt-spun at spinningtemperature of 290° C. and single hole discharge amount of 1.0 g/min outof a nozzle with a round cross section and opened while being pulled ata spinning speed of 4500 m/min and dropped on a conveyor belt below. Atthat time, the suction blow speed was controlled to be 12 m/s to obtaina web with base weight of 30 g/m² composed of long fibers with finenessof 2.2 dtex. Next, using embossing rollers having oval patterns andpress-bonding surface area of 18%, an embossing process was carried outsuccessively at embossing temperature of 150° C. and linear pressure of30 kN/m to obtain a filament nonwoven fabric for bulky layers made ofcontinuous fibers with 2.2 dtex and having base weight of 30 g/m², fiberarrangement angle of 45°, and apparent density of 0.146 g/cm³.

The above-mentioned filament nonwoven fabric for dense layers andfilament nonwoven fabric for bulky layers were subjected to interlacingtreatment by needle punch in a manner that needles could penetrate thefilament nonwoven fabric for bulky layers and the filament nonwovenfabric for dense layers successively in this order with 50penetrations/cm² and needle depth of 10 mm to obtain a layered andinterlaced nonwoven fabric for reinforcement with base weight of 60g/m².

The obtained nonwoven fabric for reinforcement was found which hasthickness of 0.62 mm, stress of 25 N/5 cm in the longitudinal directionand of 10 N/5 cm in the transverse direction, longitudinal-transverseratio (hereinafter, referred to as longitudinal/transverse ratio) at thetime of 5% elongation of 2.50, and air permeability of 200 cm³/cm²·sec.

The evaluation results of the obtained nonwoven fabrics forreinforcement are shown in Table 1. Example 1 satisfying therequirements of the present invention was found excellent in the drawingdeformation and the followability to a mold, free from bleeding andtears in the foam molding, and also excellent in the property ofadapting to a mold. In the functional evaluations, the sound suppressingproperty was good and thus Example 1 was a nonwoven fabric havingexcellent capacity for reinforcement of foam molded articles.

Example 2

PET with intrinsic viscosity of 0.65 dl/g was melt-spun at spinningtemperature of 290° C. and single hole discharge amount of 1.0 g/min outof a nozzle with a round cross section and opened while being pulled ata spinning speed of 4500 m/min and dropped on a conveyor belt below.Baffles for following current having 2 cm height and made of a punchingmetal were installed in the rim parts in the width direction of theconveyor net and the suction blow speed was controlled to be 6 m/s toobtain a web with the base weight of 40 g/m² composed of long fiberswith fineness of 2.2 dtex. Next, using embossing rollers having ovalpatterns and press-bonding surface area of 18%, an embossing process wascarried out successively at embossing temperature of 200° C. and linearpressure of 40 kN/m to obtain a filament nonwoven fabric for denselayers made of continuous fibers with 2.2 dtex and having base weight of40 g/m², fiber arrangement angle of 26°, and apparent density of 0.182g/cm³.

A filament nonwoven fabric for bulky layers with fiber arrangement angleof 48° and apparent density of 0.143 g/cm³ was obtained in the samemanner as that in Example 1, except that the conveyor speed was sochanged as to give base weight of 40 g/m² to the filament nonwovenfabric for bulky layers.

Thereafter, the interlacing treatment by needle punch was carried outsimilarly to that in Example 1 to obtain a layered and interlacednonwoven fabric for reinforcement with base weight of 80 g/m². Theobtained nonwoven fabric for reinforcement was found which has thicknessof 0.85 mm, stress of 32 N/5 cm in the longitudinal direction and of 13N/5 cm in the transverse direction, longitudinal/transverse ratio of2.46 at the time of 5% elongation, and air permeability of 160cm³/cm²·sec.

The evaluation results of the obtained nonwoven fabrics forreinforcement are shown in Table 1. Example 2 satisfying therequirements of the present invention was found excellent in the drawingdeformation and the followability to a mold, free from bleeding andtears in the foam molding, and also excellent in the property ofadapting to a mold. In the functional evaluations, the sound suppressingproperty was good and thus Example 2 was a nonwoven fabric havingexcellent capacity for reinforcement of foam molded articles.

Example 3

PET with intrinsic viscosity of 0.65 dl/g was melt-spun at spinningtemperature of 290° C. and single hole discharge amount of 1.0 g/min outof a nozzle with a round cross section and opened while being pulled ata spinning speed of 4500 m/min and dropped on a conveyor belt below.Baffles for following current having 2 cm height and made of a punchingmetal were installed in the rim parts in the width direction of theconveyor net and the suction blow speed was controlled to be 6 m/s toobtain a web with the base weight of 65 g/m² composed of long fiberswith fineness of 2.2 dtex. Next, using embossing rollers having ovalpatterns and press-bonding surface area of 18%, an embossing process wascarried out successively at embossing temperature of 150° C. and linearpressure of 30 kN/m to obtain a filament nonwoven fabric for bulkylayers made of continuous fibers with 2.2 dtex and having base weight of65 g/m², fiber arrangement angle of 28°, and apparent density of 0.151g/cm³.

Thereafter, the above-mentioned filament nonwoven fabric for bulkylayers and 40 g/m² of a filament nonwoven fabric for dense layersobtained in the same manner as that in Example 2 were subjected tointerlacing treatment by needle punch in the same manner as that inExample 1 to obtain a layered and interlaced nonwoven fabric forreinforcement with base weight of 105 g/m². The obtained nonwoven fabricfor reinforcement was found which has thickness of 1.10 mm, stress of 42N/5 cm in the longitudinal direction and of 14 N/5 cm in the transversedirection, longitudinal/transverse ratio of 3.00 at the time of 5%elongation, and air permeability of 120 cm³/cm²·sec.

The evaluation results of the obtained nonwoven fabrics forreinforcement are shown in Table 1. Example 3 satisfying therequirements of the present invention was found excellent in the drawingdeformation and the followability to a mold, free from bleeding andtears in the foam molding, and also excellent in the property ofadapting to a mold. In the functional evaluations, the sound suppressingproperty was good and thus Example 3 was a nonwoven fabric havingexcellent capacity for reinforcement of foam molded articles.

Example 4

PET with intrinsic viscosity of 0.65 dl/g was melt-spun at spinningtemperature of 290° C. and single hole discharge amount of 1.0 g/min outof a nozzle with a round cross section and opened while being pulled ata spinning speed of 4500 m/min and dropped on a conveyor belt below.Baffles for following current having 2 cm height and made of a punchingmetal were installed in the rim parts in the width direction of theconveyor net and the suction blow speed was controlled to be 4.5 m/s toobtain a web with the base weight of 40g/m² composed of long fibers withfineness of 2.2 dtex. Next, using embossing rollers having oval patternsand press-bonding surface area of 18%, an embossing process was carriedout successively at embossing temperature of 200° C. and linear pressureof 40 kN/m to obtain a filament nonwoven fabric for dense layers made ofcontinuous fibers with 2.2 dtex and having base weight of 40 g/m², fiberarrangement angle of 20°, and apparent density of 0.189 g/cm³.

Thereafter, the above-mentioned filament nonwoven fabric for denselayers and 40 g/m² of a filament nonwoven fabric for bulky layersobtained in the same manner as that in Example 2 were subjected tointerlacing treatment by needle punch in the same manner as that inExample 1 to obtain a layered and interlaced nonwoven fabric forreinforcement with base weight of 80 g/m². The obtained nonwoven fabricfor reinforcement was found which has thickness of 0.84 mm, stress of 37N/5 cm in the longitudinal direction and of 8 N/5 cm in the transversedirection, longitudinal/transverse ratio of 4.63 at the time of 5%elongation, and air permeability of 160 cm³/cm²·sec.

The evaluation results of the obtained nonwoven fabrics forreinforcement are shown in Table 1. Example 4 satisfying therequirements of the present invention was found excellent in the drawingdeformation and the followability to a mold, free from bleeding andtears in the foam molding, and also excellent in the property ofadapting to a mold. In the functional evaluations, the sound suppressingproperty was good and thus Example 4 was a nonwoven fabric havingexcellent capacity for reinforcement of foam molded articles.

Comparative Example 1

PET with intrinsic viscosity of 0.65 dl/g was melt-spun at spinningtemperature of 290° C. and single hole discharge amount of 1.0 g/min outof a nozzle with a round cross section and opened while being pulled ata spinning speed of 4500 m/min and dropped on a conveyor belt below. Atthat time, the suction blow speed was controlled to be 12 m/s to obtaina web with base weight of 40 g/m² composed of long fibers with finenessof 2.2 dtex. Next, using embossing rollers having oval patterns andpress-bonding surface area of 18%, an embossing process was carried outsuccessively at embossing temperature of 200° C. and linear pressure of40 kN/m to obtain a filament nonwoven fabric for dense layers made ofcontinuous fibers with 2.2 dtex and having base weight of 40 g/m², fiberarrangement angle of 45°, and apparent density of 0.182 g/cm³.

PET with intrinsic viscosity of 0.65 dl/g was melt-spun at spinningtemperature of 290° C. and single hole discharge amount of 1.0 g/min outof a nozzle with a round cross section and opened while being pulled ata spinning speed of 4500 m/min and dropped on a conveyor belt below. Atthat time, the suction blow speed was controlled to be 12 m/s to obtaina web with base weight of 55 g/m² composed of long fibers with finenessof 2.2 dtex. Next, using embossing rollers having oval patterns andpress-bonding surface area of 18%, an embossing process was carried outsuccessively at embossing temperature of 170° C. and linear pressure of30 kN/m to obtain a filament nonwoven fabric for bulky layers made ofcontinuous fibers with 2.2 dtex and having base weight of 55 g/m², fiberarrangement angle of 49°, and apparent density of 0.152 g/cm³.

Thereafter, the interlacing treatment by needle punch was carried outsimilarly to that in Example 1 to obtain a layered and interlacednonwoven fabric for reinforcement with base weight of 95 g/m². Theobtained nonwoven fabric for reinforcement was found which has thicknessof 0.97 mm, stress of 20 N/5 cm in the longitudinal direction and of 13N/5 cm in the transverse direction, longitudinal/transverse ratio of1.54 at the time of 5% elongation, and air permeability of 135cm³/cm²·sec.

The evaluation results of the obtained nonwoven fabrics forreinforcement are shown in Table 1. Comparative Example 1 with stress of20 N/5 cm at the time of 5% elongation in the longitudinal direction wasa nonwoven fabric which had a wider width at the time of drawing andcould not be taken out in a prescribed size.

Comparative Example 2

PET with intrinsic viscosity of 0.65 dl/g was melt-spun at spinningtemperature of 290° C. and single hole discharge amount of 1.0 g/min outof a nozzle with a round cross section and opened while being pulled ata spinning speed of 4500 m/min and dropped on a conveyor belt below. Atthat time, the suction blow speed was controlled to be 12 m/s to obtaina web with base weight of 65 g/m² composed of long fibers with finenessof 2.2 dtex. Next, using embossing rollers having oval patterns andpress-bonding surface area of 18%, an embossing process was carried outsuccessively at embossing temperature of 150° C. and linear pressure of30 kN/m to obtain a filament nonwoven fabric for bulky layers made ofcontinuous fibers with 2.2 dtex and having base weight of 65 g/m², fiberarrangement angle of 50°, and apparent density of 0.151 g/cm³.

Thereafter, the above-mentioned filament nonwoven fabric for bulkylayers and 40 g/m² of a filament nonwoven fabric for dense layersobtained in the same manner as that in Comparative Example 1 weresubjected to interlacing treatment by needle punch in the same manner asthat in Example 1 to obtain a layered and interlaced nonwoven fabric forreinforcement with base weight of 105 g/m². The obtained nonwoven fabricfor reinforcement was found which has thickness of 1.10 mm, stress of 25N/5 cm in the longitudinal direction and of 17 N/5 cm in the transversedirection, longitudinal/transverse ratio of 1.47 at the time of 5%elongation, and air permeability of 122 cm³/cm²·sec.

The evaluation results of the obtained nonwoven fabrics forreinforcement are shown in Table 1. Although being good in both drawingdeformation and followability to a mold, Comparative Example 2 withstress of 17 N/5 cm at the time of 5% elongation in the transversedirection was a nonwoven fabric which had high stress in the transversedirection and was slightly inferior in the property of adapting to amold and was thus problematic.

Comparative Example 3

PET with intrinsic viscosity of 0.65 dl/g was melt-spun at spinningtemperature of 290° C. and single hole discharge amount of 1.0 g/min outof a nozzle with a round cross section and opened while being pulled ata spinning speed of 4500 m/min and dropped on a conveyor belt below. Atthat time, the suction blow speed was controlled to be 12 m/s to obtaina web with base weight of 30 g/m² composed of long fibers with finenessof 2.2 dtex. Next, using embossing rollers having oval patterns andpress-bonding surface area of 18%, an embossing process was carried outsuccessively at embossing temperature of 200° C. and linear pressure of40 kN/m to obtain a filament nonwoven fabric for dense layers made ofcontinuous fibers with 2.2 dtex and having base weight of 30 g/m², fiberarrangement angle of 45°, and apparent density of 0.185 g/cm³.

Thereafter, the above-mentioned filament nonwoven fabric for denselayers and 30 g/m² of a filament nonwoven fabric for bulky layersobtained in the same manner as that in Example 1 were subjected tointerlacing treatment by needle punch in the same manner as that inExample 1 to obtain a layered and interlaced nonwoven fabric forreinforcement with base weight of 60 g/m². The obtained nonwoven fabricfor reinforcement was found which has thickness of 0.62 mm, stress of 18N/5 cm in the longitudinal direction and of 13 N/5 cm in the transversedirection, longitudinal/transverse ratio of 1.38 at the time of 5%elongation, and air permeability of 204 cm³/cm²·sec.

The evaluation results of the obtained nonwoven fabrics forreinforcement are shown in Table 1. Comparative Example 3 with stress of18 N/5 cm at the time of 5% elongation in the longitudinal direction wasa nonwoven fabric which had a wider width at the time of drawing andcould not be taken out in a prescribed size.

Comparative Example 4

PET with intrinsic viscosity of 0.65 dl/g was melt-spun at spinningtemperature of 290° C. and single hole discharge amount of 2.0 g/min outof a nozzle with a round cross section and opened while being pulled ata spinning speed of 4500 m/min and dropped on a conveyor belt below.Baffles for following current having 2 cm height and made of a punchingmetal were installed in the rim parts in the width direction of theconveyor net and the suction blow speed was controlled to be 8 m/s toobtain a web with the base weight of 30g/m² composed of long fibers withfineness of 4.4 dtex. Next, using embossing rollers having oval patternsand press-bonding surface area of 18%, an embossing process was carriedout successively at embossing temperature of 200° C. and linear pressureof 40 kN/m to obtain a filament nonwoven fabric for dense layers made ofcontinuous fibers with 4.4 dtex and having base weight of 30 g/m², fiberarrangement angle of 20°, and apparent density of 0.178 g/cm³.

PET with intrinsic viscosity of 0.65 dl/g was melt-spun at spinningtemperature of 290° C. and single hole discharge amount of 2.0 g/min outof a nozzle with a round cross section and opened while being pulled ata spinning speed of 4500 m/min and dropped on a conveyor belt below. Atthat time, the suction blow speed was controlled to be 12 m/s to obtaina web with base weight of 30 g/m² composed of long fibers with finenessof 4.4 dtex. Next, using embossing rollers having oval patterns andpress-bonding surface area of 18%, an embossing process was carried outsuccessively at embossing temperature of 150° C. and linear pressure of30 kN/m to obtain a filament nonwoven fabric for bulky layers made ofcontinuous fibers with 4.4 dtex and having base weight of 30 g/m², fiberarrangement angle of 42°, and apparent density of 0.133 g/cm³.

Thereafter, the interlacing treatment by needle punch was carried outsimilarly to that in Example 1 to obtain a layered and interlacednonwoven fabric for reinforcement with base weight of 60 g/m². Theobtained nonwoven fabric for reinforcement was found which has thicknessof 0.66 mm, stress of 25 N/5 cm in the longitudinal direction and of 9N/5 cm in the transverse direction, longitudinal/transverse ratio of2.78 at the time of 5% elongation, and air permeability of 315cm³/cm²·sec.

The evaluation results of the obtained nonwoven fabrics forreinforcement are shown in Table 1. Although being good in both drawingdeformation and followability to a mold, Comparative Example 4 with airpermeability of 315 cm³/cm²·sec caused bleeding of urethane in foammolding and was inferior in the sound suppressing property for a moldedarticle.

TABLE 1 Com- Com- Com- Com- Example Example Example Example parativeparative parative parative item unit 1 2 3 4 Example 1 Example 2 Example3 Example 4 dense baffles for following — install install installinstall not install not install not install install layers currentsuction blow speed m/sec 8 6 6 4.5 12 12 12 8 using nonwoven fabric —filament filament filament filament filament filament filament filamentbase weight g/m² 30 40 40 40 40 40 30 30 apparent density g/cm³ 0.1850.182 0.182 0.189 0.182 0.182 0.185 0.178 fineness dtex 2.2 2.2 2.2 2.22.2 2.2 2.2 4.4 bulky baffles for following — not not install not notnot install not install not install layers current install installinstall install suction blow speed m/sec 12 12 6 12 12 12 12 12 usingnonwoven fabric — filament filament filament filament filament filamentfilament filament base weight g/m² 30 40 65 40 55 65 30 30 apparentdensity g/cm² 0.146 0.143 0.151 0.143 0.152 0.151 0.146 0.133 finenessdtex 2.2 2.2 2.2 2.2 2.2 2.2 2.2 4.4 nonwoven total base weight g/m 6080 105 80 95 105 60 60 fabric for thickness mm 0.62 0.85 1.10 0.84 0.971.10 0.62 0.66 reinforce- Stress at the longitudinal N/5 cm 25 32 42 3720 25 18 25 ment time of 5% transverse N/5 cm 10 13 14 8 13 17 13 9elongation longitudinal-transverse — 2.50 2.46 3.00 4.63 1.54 1.47 1.382.78 ratio at the time of 5% elongation gas permeability cm³/ 200 160120 160 135 122 204 315 cm² · sec process passing property — ∘ ∘ ∘ ∘ Δ ∘Δ ∘ (drawing deformation) Foam followability to a mold — ∘ ∘ ∘ ∘ x ∘ x ∘mold- bleeding — ∘ ∘ ∘ ∘ ∘ ∘ ∘ Δ ability tearing — ∘ ∘ ∘ ∘ ∘ ∘ ∘ ∘property of adapting — ∘ ∘ ∘ ∘ ∘ Δ ∘ ∘ to mold perform- soundsuppression — ∘ ∘ ∘ ∘ ∘ ∘ ∘ x ance of molded article

Example 5

PET with intrinsic viscosity of 0.65 dl/g was melt-spun at 290° C. andsingle hole discharge amount of 1.0 g/min out of a nozzle with a roundcross section and opened while being pulled at a spinning speed of 4500m/min and dropped on a suction net below. Baffles for following currenthaving 2 cm height and made of a punching metal were installed in therim parts in the width direction of the suction net and the suction blowspeed was controlled to be 8.0 m/s to obtain a web composed of longfibers with fineness of 2.2 dtex. Next, using embossing rollers havingoval patterns and press-bonding surface area of 18%, an embossingprocess was carried out at temperature of 200° C. and linear pressure of40 kN/m to obtain a filament nonwoven fabric for dense layers with baseweight of 40 g/m².

PET with intrinsic viscosity of 0.65 dl/g was melt-spun at spinningtemperature of 290° C. and single hole discharge amount of 1.0 g/min outof a nozzle with a round cross section and opened while being pulled ata spinning speed of 4500 m/min and dropped on a suction net below.Baffles for following current having 2 cm height and made of a punchingmetal were installed in the rim parts in the width direction of thesuction net and the suction blow speed was controlled to be 8.0 m/s toobtain a web composed of long fibers with fineness of 2.2 dtex. Next,using embossing rollers having oval patterns and press-bonding surfacearea of 18%, an embossing process was carried out at temperature of 180°C. and linear pressure of 40 kN/m to obtain a filament nonwoven fabricfor bulky layers with base weight of 40 g/m².

The obtained filament nonwoven fabric for dense layers and filamentnonwoven fabric for bulky layers were subjected to interlacing treatmentby needle punch in a manner that needles could penetrate the filamentnonwoven fabric for bulky layers and the filament nonwoven fabric fordense layers successively in this order with 50 penetrations/cm² andneedle depth of 10 mm to obtain a nonwoven fabric for reinforcement.

The physical properties of the filament nonwoven fabrics and thenonwoven fabrics for reinforcement and the foam molding property areshown in Table 2.

Example 6

A nonwoven fabric for reinforcement was obtained in the same manner asthat in Example 5, except that the suction blow speed was changed to be6.0 m/s in the condition for producing the filament nonwoven fabric fordense layers and bulky layers.

The physical properties of the filament nonwoven fabrics and thenonwoven fabrics for reinforcement and the foam molding property areshown in Table 2.

Example 7

A nonwoven fabric for reinforcement was obtained in the same manner asthat in Example 5, except that the suction blow speed was changed to be4.5 m/s in the condition for producing the filament nonwoven fabric fordense layers and bulky layers.

The physical properties of the filament nonwoven fabrics and thenonwoven fabrics for reinforcement and the foam molding property areshown in Table 2.

Example 8

A nonwoven fabric for reinforcement was obtained in the same manner asthat in Example 6, except that the base weight of the filament nonwovenfabric for bulky layers is 60 g/m².

The physical properties of the filament nonwoven fabrics and thenonwoven fabrics for reinforcement and the foam molding property areshown in Table 2.

Example 9

A nonwoven fabric for reinforcement was obtained in the same manner asthat in Example 6, except that the baffles for following current weretaken out, and the suction blow speed was changed to be 12.0 m/s in thecondition for producing the filament nonwoven fabric for bulky layers.

The physical properties of the filament nonwoven fabrics and thenonwoven fabrics for reinforcement and the foam molding property areshown in Table 2.

Example 10

A nonwoven fabric for reinforcement was obtained in the same manner asthat in Example 5, except that the suction blow speed was changed to be3.3 m/s, and the embossing process temperature was changed to be 210° C.in the condition for producing the filament nonwoven fabric for denselayers and the suction blow speed was changed to be 12.0 m/s in thecondition for producing the filament nonwoven fabric for bulky layers.

The physical properties of the filament nonwoven fabrics and thenonwoven fabrics for reinforcement and the foam molding property areshown in Table 2.

Comparative Example 5

A nonwoven fabric for reinforcement was obtained in the same manner asthat in Example 5, except that the baffles for following current weretaken out, and the suction blow speed was changed to be 12.0 m/s in thecondition for producing the filament nonwoven fabric for dense layersand bulky layers.

The physical properties of the filament nonwoven fabrics and thenonwoven fabrics for reinforcement and the foam molding property areshown in Table 2.

Comparative Example 6

A nonwoven fabric for reinforcement was obtained in the same manner asthat in Example 5, except that the baffles for following current weretaken out, the suction blow speed was changed to be 12.0 m/s, and theembossing process temperature was changed to be 220° C. in the conditionfor producing the filament nonwoven fabric for dense layers and thebaffles for following current were taken out, the suction blow speed waschanged to be 12.0 m/s, and the embossing process temperature waschanged to be 200° C. in the condition for producing the filamentnonwoven fabric for bulky layers.

The physical properties of the filament nonwoven fabrics and thenonwoven fabrics for reinforcement and the foam molding property areshown in Table 2.

From Table 2, it can be understood that the nonwoven fabrics forreinforcement of Examples 5 to 10 were excellent in the foam moldingproperty and the nonwoven fabrics for reinforcement of ComparativeExamples 5 and 6 were inferior in the foam molding property.

TABLE 2 Ex- Com- Com- Example Example Example Example Example ampleparative parative item unit 5 6 7 8 9 10 Example 5 Example 6 densebaffles for following current — install install install install installinstall not install not install layers suction blow speed m/sec 8.0 6.04.5 6.0 6.0 3.3 12.0 12.0 embossing temperature ° C. 200 200 200 200 200210 200 220 process linear pressure kN/m 40 40 40 40 40 40 40 40 baseweight g/m² 40 40 40 40 40 40 40 40 apparent density g/cm³ 0.171 0.1710.171 0.171 0.171 0.171 0.171 0.171 bulky baffles for following current— install install install install not install install not install notinstall layers suction blow speed m/sec 8.0 6.0 4.5 6.0 12.0 12.0 12.012.0 embossing temperature ° C. 180 180 180 180 180 180 180 200 processlinear pressure kN/m 40 40 40 40 40 40 40 40 base weight g/m² 40 40 4060 40 40 40 40 apparent density g/cm³ 0.159 0.159 0.159 0.159 0.1590.159 0.159 0.159 nonwoven total base weight g/m² 80 80 80 100 80 80 8080 fabric for dry heat longitudinal % 0.1 0 −0.02 0.35 −0.02 0.35 2.20.2 reinforce- shrinkage rate transverse % −0.01 −0.01 0 0.2 −0.05 0.20.7 0 ment tear strength longitudinal N 41 38 37 57 38 29 41 18transverse N 35 36 36 55 35 35 30 14 stress at the longitudinal N/5 cm30 32 35 38 30 44 18 45 time of 5% transverse N/5 cm 12 10 8 15 18 10 1020 elongation Foam followability to a mold — ∘ ∘ ∘ ∘ Δ Δ ∘ ∘ mold-wrinkle — ∘ ∘ ∘ ∘ ∘ ∘ x ∘ ability tearing — ∘ ∘ ∘ ∘ ∘ ∘ ∘ x

INDUSTRIAL APPLICABILITY

The nonwoven fabric for reinforcement of the present invention isparticularly excellent in dimensional stability in the cutting/sewingstep although flexible. The nonwoven fabric for reinforcement of thepresent invention is composed of a dense layer with shutting function ofa high foamable resin and a bulky layer excellent in a sound suppressionproperty and is excellent in a close adhesion property between a foammolded part and the nonwoven fabric for reinforcement because of theanchor effect attributed to an extruded fiber structure and isaccordingly a nonwoven fabric optimum for application as reinforcingcloth for foam molding. Consequently, followability to a mold at thetime of foam molding is excellent and a high grade foam molded articlecan be obtained without bleeding of a foamable resin. Further, thenonwoven fabric for reinforcement is excellent in a sound suppressingproperty to the frictional sound generated by friction between the foammolded article and springs and also excellent in a reinforcing effectand durability and is thus suitable for use as a reinforcing cloth toobtain highly functional foam molded articles at saved production cost.

Still further, since being relatively lightweight, the nonwoven fabricfor reinforcement of the present invention is useful for economicallyproducing a lightweight and high grade foam molded article andcontributes to making a vehicular seat using the foam molded articleeconomical and lightweight and also to saving energy in terms of drivingthe vehicle.

1. A nonwoven fabric for reinforcing foam molded articles formed byinterlacing at least 2 filament nonwoven fabric layers with differentapparent density, wherein the nonwoven fabric has dry heat shrinkagerate of −1 to 2% in both longitudinal and transverse directions at thetime of heat treatment at 80° C. for 30 minutes and tear strength of 20N or higher in both longitudinal and transverse directions.
 2. Thenonwoven fabric for reinforcing foam molded articles as claimed in claim1, wherein all of the nonwoven fabric layers have apparent density ofhigher than 0.15 g/cm³.
 3. The nonwoven fabric for reinforcing foammolded articles as claimed in claim 1, wherein the stress at the time of5% elongation in longitudinal direction is 20 to 45 N/5 cm and thestress at the time of 5% elongation in transverse direction is 19 N/5 cmor lower.
 4. The nonwoven fabric for reinforcing foam molded articles asclaimed in claim 1, wherein the stress at the time of 5% elongation inlongitudinal direction is 30 to 45 N/5 cm and the stress at the time of5% elongation in transverse direction is 15 N/5 cm or lower.
 5. Thenonwoven fabric for reinforcing foam molded articles as claimed in claim2, wherein the stress at the time of 5% elongation in longitudinaldirection is 20 to 45 N/5 cm and the stress at the time of 5% elongationin transverse direction is 19 N/5 cm or lower.
 6. The nonwoven fabricfor reinforcing foam molded articles as claimed in claim 2, wherein thestress at the time of 5% elongation in longitudinal direction is 30 to45 N/5 cm and the stress at the time of 5% elongation in transversedirection is 15 N/5 cm or lower.
 7. The nonwoven fabric for reinforcingfoam molded articles as claimed in claim 1, wherein the filamentnonwoven fabrics are made of polyester fibers.
 8. The nonwoven fabricfor reinforcing foam molded articles as claimed in claim 2, wherein thefilament nonwoven fabrics are made of polyester fibers.
 9. The nonwovenfabric for reinforcing foam molded articles as claimed in claim 3,wherein the filament nonwoven fabrics are made of polyester fibers. 10.The nonwoven fabric for reinforcing foam molded articles as claimed inclaim 4, wherein the filament nonwoven fabrics are made of polyesterfibers.
 11. The nonwoven fabric for reinforcing foam molded articles asclaimed in claim 5, wherein the filament nonwoven fabrics are made ofpolyester fibers.
 12. The nonwoven fabric for reinforcing foam moldedarticles as claimed in claim 6, wherein the filament nonwoven fabricsare made of polyester fibers.
 13. A foam molded article, wherein thenonwoven fabric for reinforcing foam molded articles as claimed in claim1 is used as a reinforcing cloth.
 14. The foam molded article as claimedin claim 13, wherein the filament nonwoven fabric with higher apparentdensity between 2 layers of filament nonwoven fabric with differentdensity is arranged in the foamed body side of the foam molded article.